Helicobacter pyloriの除菌により改善をみた胃MALTリンパ腫の1例―免疫グロブリン遺伝子再構成の変動とともに

Regression of Gastric MALT-lymphoma by the Eradication of Helicobacter pylori, Report of a Case: The Change of the Rearrangement of Immunoglobulin Heavy Chain DNA was Observed

要旨　Isaacsonらが提唱した胃MALTリンパ腫は，その後彼らによりHelicobacter Pylori（H. Pylori）の存在下で発症し，その除菌によって病変の消退することが報告された．筆者らは最近，胃角部大彎側にびらん性陥凹を認めた38歳の女性に対し，生検によりMALTリンパ腫を疑い，更に免疫グロブリン遺伝子IgH-J鎖の明らかな再構成バンドを認めたためMALTリンパ腫と確定診断した．Hpylori感染下にあることを確認後除菌療法を行ったところ，2か月後から病変は消失し異型細胞は激減した．一方，IgH-J鎖の再構成バンドも著明に減少した．しかし7か月後に至ってもかすかに陽性で，いまだ単クローン性Bリンパ球の胃粘膜内での残存を意味した．しかしながらH. Pyloriの胃MALTリンパ腫への関与と，その除菌により本症の改善する可能性が強く示唆された．

　Recently, it has been reported that Helicobacter pylori (H. pylori) infection is involved in the development of low grade B-cell gastric lymphoma (MALT-oma), and that six cases of MALT-oma were improved by eradicating H. pylori. Therefore, the authors eradicated H. pylori in a 38-year-old female patient with gastric MALT-oma. Two months after the end of the treatment the MALT-oma lesion in the stomach of the patient had disappeared endoscopically, but slightly remained histologically. In addition, a dramatic decrease of the intensity of the rearranged bands of immunoglobulin heavy chain (IgH) DNA was noted. However, in spite of continuous remission of MALT-oma for more than six months, a very minute rearranged band of IgH DNA was still detected by increasing the exposure time of the gel even at seven months after the treatment. Thus, it is strongly suggested that H. pylori infection somehow played a role in the pathogenesis of gastric MALT-oma in our patient, and that eradication of H. pylori is the first choice treatment for patient with gastric MALT-oma. Whether or not the rearranged bands of IgH DNA will completely disappear in the near future in this patient remains to be examined.